transaction.c

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/*
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: 558098858a58515da0ecf99edcdad57a6554eb9c $
 *
 * @file unlang/transaction.c
 * @brief Allows for edit transactions
 *
 * @copyright 2023 Network RADIUS SAS (legal@networkradius.com)
 */
 
RCSID("$Id: 558098858a58515da0ecf99edcdad57a6554eb9c $")
 
#include <freeradius-devel/util/syserror.h>
#include <freeradius-devel/server/rcode.h>
#include "transaction.h"
#include "transaction_priv.h"
 
/** Signal a transaction to abort.
 *
 * @param[in] request           The current request.
 * @param[in] frame             being signalled.
 * @param[in] action            to signal.
 */
static void unlang_transaction_signal(UNUSED request_t *request, unlang_stack_frame_t *frame, fr_signal_t action)
{
        unlang_frame_state_transaction_t *state = talloc_get_type_abort(frame->state,
                                                                        unlang_frame_state_transaction_t);
 
        /*
         *      Ignore everything except cancel.
         */
        if (action != FR_SIGNAL_CANCEL) return;
 
        fr_edit_list_abort(state->el);
        state->el = NULL;
}
 
/** Commit a successful transaction.
 *
 */
static unlang_action_t unlang_transaction_final(UNUSED unlang_result_t *p_result, UNUSED request_t *request,
                                                unlang_stack_frame_t *frame)
{
        unlang_frame_state_transaction_t *state = talloc_get_type_abort(frame->state,
                                                                        unlang_frame_state_transaction_t);
 
        fr_assert(state->el != NULL);
 
        /*
         *      p_result contains OUR result, we want the section
         *      result from what was just executed on the stack.
         */
        switch (state->result.rcode) {
        case RLM_MODULE_REJECT:
        case RLM_MODULE_FAIL:
        case RLM_MODULE_INVALID:
        case RLM_MODULE_DISALLOW:
        case RLM_MODULE_NOTFOUND:
        case RLM_MODULE_TIMEOUT:
                fr_edit_list_abort(state->el);
                break;
 
        case RLM_MODULE_OK:
        case RLM_MODULE_HANDLED:
        case RLM_MODULE_NOOP:
        case RLM_MODULE_UPDATED:
        case RLM_MODULE_NOT_SET:
                fr_edit_list_commit(state->el);
                break;
 
        case RLM_MODULE_NUMCODES:       /* Do not add default: */
                fr_assert(0);
                return UNLANG_ACTION_FAIL;
        }
 
        /*
         *      Allow the interpreter to access
         *      the result of the child section
         */
        *p_result = state->result;
 
        return UNLANG_ACTION_CALCULATE_RESULT;
}
 
static unlang_action_t unlang_transaction(UNUSED unlang_result_t *p_result, request_t *request, unlang_stack_frame_t *frame)
{
        unlang_frame_state_transaction_t        *state = talloc_get_type_abort(frame->state, unlang_frame_state_transaction_t);
        fr_edit_list_t *parent;
 
        parent = unlang_interpret_edit_list(request);
 
        MEM(state->el = fr_edit_list_alloc(state, 10, parent));
 
        frame_repeat(frame, unlang_transaction_final);
 
        return unlang_interpret_push_children(&state->result, request, RLM_MODULE_NOT_SET, UNLANG_NEXT_SIBLING);
}
 
fr_edit_list_t *unlang_interpret_edit_list(request_t *request)
{
        unlang_stack_frame_t    *frame;
        unlang_stack_t          *stack = request->stack;
        int                     i, depth = stack->depth;
 
        if (depth == 1) return NULL;
 
        for (i = depth - 1; i > 0; i--) {
                unlang_frame_state_transaction_t *state;
 
                frame = &stack->frame[i];
                if (frame->instruction->type != UNLANG_TYPE_TRANSACTION) continue;
 
                state = talloc_get_type_abort(frame->state, unlang_frame_state_transaction_t);
                fr_assert(state->el != NULL);
 
                return state->el;
        }
 
        return NULL;
}
 
static fr_table_num_sorted_t transaction_keywords[] = {
        { L("case"),            1 },
        { L("catch"),           1 },
        { L("else"),            1 },
        { L("elsif"),           1 },
        { L("foreach"),         1 },
        { L("group"),           1 },
        { L("if"),              1 },
        { L("limit"),           1 },
        { L("load-balance"),    1 },
        { L("map"),             1 },
        { L("redundant"),       1 },
        { L("redundant-load-balance"), 1 },
        { L("switch"),          1 },
        { L("timeout"),         1 },
        { L("transaction"),     1 },
        { L("try"),             1 },
};
static int transaction_keywords_len = NUM_ELEMENTS(transaction_keywords);
 
/** Limit the operations which can appear in a transaction.
 */
static bool transaction_ok(CONF_SECTION *cs)
{
        CONF_ITEM *ci = NULL;
 
        while ((ci = cf_item_next(cs, ci)) != NULL) {
                char const *name;
 
                if (cf_item_is_section(ci)) {
                        CONF_SECTION *subcs;
 
                        subcs = cf_item_to_section(ci);
                        name = cf_section_name1(subcs);
 
                        /*
                         *      Allow limited keywords.
                         */
                        if ((strcmp(name, "actions") == 0) ||
                            (strcmp(name, "if") == 0) ||
                            (strcmp(name, "else") == 0) ||
                            (strcmp(name, "elsif") == 0)) {
                                continue;
                        }
 
                        /*
                         *      Ignore edits.
                         */
                        if (fr_list_assignment_op[cf_section_name2_quote(subcs)]) continue;
 
                        if (fr_table_value_by_str(transaction_keywords, name, -1) < 0) {
                                cf_log_err(ci, "Invalid keyword in 'transaction'");
                                return false;
                        }
 
                        if (!transaction_ok(subcs)) return false;
 
                        continue;
 
                } else if (cf_item_is_pair(ci)) {
                        CONF_PAIR *cp;
 
                        cp = cf_item_to_pair(ci);
                        name = cf_pair_attr(cp);
 
                        /*
                         *      If there's a value then it's not a module call.
                         */
                        if (cf_pair_value(cp)) continue;
 
                        /*
                         *      Allow rcodes via the "always" module.
                         */
                        if (fr_table_value_by_str(mod_rcode_table, name, -1) >= 0) {
                                continue;
                        }
 
                        cf_log_err(ci, "Invalid module reference in 'transaction'");
                        return false;
 
                } else {
                        continue;
                }
        }
 
        return true;
}
 
static unlang_t *unlang_compile_transaction(unlang_t *parent, unlang_compile_ctx_t *unlang_ctx, CONF_ITEM const *ci)
{
        CONF_SECTION *cs = cf_item_to_section(ci);
        unlang_group_t *g;
        unlang_t *c;
        unlang_compile_ctx_t unlang_ctx2;
 
        if (cf_section_name2(cs) != NULL) {
                cf_log_err(cs, "Unexpected argument to 'transaction' section");
                cf_log_err(ci, DOC_KEYWORD_REF(transaction));
                return NULL;
        }
 
        /*
         *      The transaction is empty, ignore it.
         */
        if (!cf_item_next(cs, NULL)) return UNLANG_IGNORE;
 
        if (!transaction_ok(cs)) return NULL;
 
        g = unlang_group_allocate(parent, cs, UNLANG_TYPE_TRANSACTION);
        if (!g) return NULL;
 
        c = unlang_group_to_generic(g);
        c->debug_name = c->name = cf_section_name1(cs);
 
        /*
         *      The default for a failed transaction is to continue to
         *      the next instruction on failure.
         */
        c->actions.actions[RLM_MODULE_FAIL] = MOD_PRIORITY(1);
        c->actions.actions[RLM_MODULE_INVALID] = MOD_PRIORITY(1);
        c->actions.actions[RLM_MODULE_DISALLOW] = MOD_PRIORITY(1);
 
        /*
         *      For the children of this keyword, any failure is
         *      return, not continue.
         */
        unlang_compile_ctx_copy(&unlang_ctx2, unlang_ctx);
 
        unlang_ctx2.actions.actions[RLM_MODULE_REJECT] = MOD_ACTION_RETURN;
        unlang_ctx2.actions.actions[RLM_MODULE_FAIL] = MOD_ACTION_RETURN;
        unlang_ctx2.actions.actions[RLM_MODULE_INVALID] = MOD_ACTION_RETURN;
        unlang_ctx2.actions.actions[RLM_MODULE_DISALLOW] = MOD_ACTION_RETURN;
 
        return unlang_compile_children(g, &unlang_ctx2);
}
 
void unlang_transaction_init(void)
{
        unlang_register(&(unlang_op_t){
                        .name = "transaction",
                        .type = UNLANG_TYPE_TRANSACTION,
                        .flag = UNLANG_OP_FLAG_DEBUG_BRACES,
 
                        .compile = unlang_compile_transaction,
                        .interpret = unlang_transaction,
                        .signal = unlang_transaction_signal,
 
                        .unlang_size = sizeof(unlang_transaction_t),
                        .unlang_name = "unlang_transaction_t",
 
                        .frame_state_size = sizeof(unlang_frame_state_transaction_t),
                        .frame_state_type = "unlang_frame_state_transaction_t",
                });
}